1. Field of the Invention
The present invention relates generally to manually used shovels, such as are typically utilized for cutting through soil, grass roots and small tree roots as the user digs into soil. More particularly, the present invention concerns a root cutting shovel having the capability for cutting through tree roots that cannot ordinarily be cut by conventional shovels and cutting through surface oriented grass and weed roots to enable efficient handling of the soil, including consolidated soil or loose soil, being shoveled. Even more particularly, the present invention concerns a shovel geometry that enables the soil load being cut away and removed by the shovel to remain on the blade of the shovel as the soil is cut and lifted, thus minimizing the labor that is ordinarily needed for general shoveling activities.
2. Description of the Prior Art
Though a wide variety of shovels have been developed for a wide variety of specific shoveling needs, the present invention is directed generally to round point shovels having a long straight handle or a D-handle. Round point shovels typically have a curved shovel blade with a concave blade face directed in a forward direction, away from the user and a convex blade face directed rearwadly or toward the user. At its rear end the shovel blade typically define a tubular handle connector that is typically of curved configuration and which receives a shovel handle of the long straight type or of the D-handle type. The tubular handle typically extends from the central region of the shovel blade, being forged or otherwise formed by the blade structure and extends upwardly well beyond the upper edge of the shovel blade where it forms a receptacle to receive the shovel handle. The tubular handle connector or receptacle is typically of tapered internal configuration and the lower end of the handle is likewise tapered to establish a good surface-to-surface fit between the handle connector and handle.
The handle connector is typically oriented with respect to the shovel blade to provide for angulation or inclination of the longitudinal center-line of the shovel blade relative to the shovel handle. This angulation or inclination of the shovel blade relative to the shovel handle permits the shovel blade to be oriented at a slightly inclined relation with the horizontal, with the shovel blade at ground level, while the handle of the shovel is positioned with its upper end at substantially waist or hip level of a user. In this shovel position the blade of the shovel can be used efficiently to skim or skin a substantially flat section of soil or remove grass and weeds from the surface of the soil without deeply disturbing the soil. This feature permits a round point shovel to be efficiently utilized for contouring or controlling the configuration of the surface of the soil. A D-handle for a round point shovel is typically short and the D-handle fitting at the upper end of the handle defines upwardly diverging handle elements which support a transversely oriented griping element of a size for efficient gripping by the gloved or non-gloved hand of a user. A straight shovel handle is typically significantly longer as compared to a D-handle and thus provides significantly greater leverage for efficient shovel use when the soil being cut is of fairly consolidated nature. A user will typically select between a straight handled shovel or a D-handled shovel to suit the shoveling job that is intended.
On each side of the tubular handle connector, the upper portion of the shovel blade defines foot engaging flanges or is provided with a foot engaging element or fitment having a flat surface that is engaged by the right or left foot of the user, as the case may be, thus enabling the user to apply manual force to the shovel blade with the user""s foot to drive the shapened forward end of the shovel blade into the soil being cut. On each side of the curved shovel blade side edges are defined which are typically disposed in substantially parallel relation and extend from the rear end portion of the blade. Typically, these side edges are oriented at angles of about 90xc2x0 with respect to the rear flanged end of the shovel blade and extend downward toward the point of the blade. Typically, the substantially parallel related side edges extend along about the upper third or half of the shovel blade. From this region of a round point shovel blade, the side edges are gradually curved and disposed in converging relation so that they meet at a central point at the lower end of the shovel blade, essentially at the longitudinal center-line of the blade. In some cases, the side edges of the shovel blade are oriented in slightly downwardly converging relation from the upper flanged foot engaging edges of the blade and become more and more curved as the side edges approach the lower pointed end of the blade.
From approximately the lower third of the shovel blade to the centrally located point, the concave portions of the side edges are beveled to define a sharp cutting edge at the interstion of the beveled surface with the convex rear face of the shovel blade. Typically a user of a shovel of this type will frequently file or hone the cutting edge of the blade because, during use, the abrasive characteristics of typical soil will wear away and dull the cutting edge. For this reason, quality shovels have hardened blades to minimize wear and dulling of the cutting edge during normal use.
One of the disadvantages of round point shovels is their inability to cut through tree roots of significant dimension. Though efficient for cutting through grass and weed roots, except at the side of the shovel blade, and for cutting through the small feeder roots of trees, i.e., those roots having a diameter of from xc2xcxe2x80x3 to xc2xdxe2x80x3, a round point shovel will function quite efficiently. These shovels, unless extremely sharp, will seldom cut through tree roots exceeding xc2xdxe2x80x3 in diameter. Also, when round point shovels come into contact with a tree root they tend to rotate or slide laterally rather than cut through the root because the curved end of the shovel blade, on either side of the sharp point, is typically forced to move laterally by the root, rather than cutting through the root. When a tree root in encountered, for the most part, it is necessary to utilize another implement, such as an axe, to cut through the tree root at each side of the hole being dug, so that the offending section of the root can be removed from the shoveling area.
Another problem with round point shovels is the loss of shovel load when small roots such as the surface roots of grass and small feeder roots of trees remain in the soil at the edges of the shovel. Typically when cutting through soil with a round point shovel, the blade of the shovel will cut into the soil, but the soil at the side edges of the shovel blade will typically contain surface roots which are not cut by the shovel. When the shovel handle is manipulated pivotally about the blade to loosen a section of soil that has been cut, the remaining surface roots at the side edges of the shovel blade will provide resistance to movement of the edges of the soil load of the shovel blade. More often than not, the resistance of the surface roots at the side edges of the shovel blade will be uneven, so that the blade tends to be ted by greater soil and root resistance at one of the side edges as compared with the other. When this occurs, the shovel blade will rotate as soil loosening force is applied and much if not all of the soil load of the shovel will be lost. The user will then be required to use the shovel in a chopping action to cut the lateral surface roots before the intended soil section can be efficiently removed. This, of course, significantly increases the manual labor that is required for soil cutting and removal. It is desirable therefore to provide a round point type shovel which accomplishes lateral surface root cutting as well as conventional blade cutting during use and which therefore does not tend to be rotated by lateral surface root resistance as sections of soil are cut, loosened and removed.
Another problem typically occurs when round point shovels are utilized and tree roots are encountered. A user, typically an inexperienced user, will force the point of the shovel beneath the root and then apply a prying action in an attempt to cause the shovel blade to break through a root. When this is done, the force applied will often break a wooden shovel handle, thus requiring that the shovel be rehandled at significant labor and expense or discarded and replaced. It is thus desirable to provide a round point type shovel having a geometry or configuration that minimizes the occurrence of broken shovel handles even when the shovel is being utilized by a novice. It is also desirable to provide a round point type shovel having the capability for efficiently cutting trough tree roots, including surface feeder roots without necessitating the use of a chopping action when these are encountered during shoveling activities.
It is a principal feature of the present invention to provide a novel shovel having a round point type shovel blade which is efficient for cutting through tree roots up to two inches or more in diameter when such roots are encountered during shoveling activities;
It is another feature of the present invention to provide a novel shovel having a round point type shovel blade which defines a flattened lower cutting edge section to minimize lateral camming activity as roots are encountered and to make root cutting more effective with the lower cutting edge of the shovel blade;
It is an even further feature of the present invention to provide a novel shovel having a round point type shovel blade which incorporates a central root cutting blade having a forwardly oriented straight, convex or concave cutting edge which permits efficient cutting of tree roots by employing a prying action of the shovel handle;
It is also a feature of the present invention to provide a novel shovel having a round point type shovel blade which has a centrally located root cutting blade projecting in substantially normal relation from the central concave surface of the shovel blade and which defines a shapened lower edge which efficiently contacts and cuts through tree roots as the shovel blade is forced through root containing soil;
It is another feature of the present invention to provide a novel shovel having a round point type shovel blade which is provided, and with side blades being provided at each of the side edges of the shovel blade and which are oriented for cutting through surface roots and thus minimize the potential for shovel blade rotation by uneven blade edge forces; and
It is an even further feature of the present invention to provide a novel shovel having a round point type shovel blade having side edge blades each having a sharpened forwardly directed cutting edge for efficient cutting through surface roots of the soil as the shovel blade is forced trough the soil by foot applied manual force.
Briefly, the various objects and features of the present invention are realized through the provision of a manually used shovel having a blade from which extends a handle connector having a suitable handle connected therein. The handle may be of the straight type or of the D-handle type and may be composed of wood, fiberglass, metal or any suitable plastics material or plastics composite. The shovel blade is preferably composed of metal, such as hardened steel, or it may be composed of any other material or combinations of materials that is suitable for the purpose intended.
From the concave front face of the shovel blade a root cutting blade is fixed along the longitudinal center-line of the shovel blade and projects in substantially normal relation with the concave face. Preferably, the central root cutting blade extends from the upper edge of the shovel blade to a location approximately one or two inches from the forward end of the shovel blade, though, if desired, the central root cutting blade may extend completely from the rear end to the sharpened forward end of the shovel blade. Alternatively, the root cutting blade may be fixed to the shovel blade along the longitudinal center-line, with the forward and rearward ends thereof being located short of the forward and rear ends of the shovel blade. The central root cutting blade is preferably configured at its lower end to define a sharpened root cutting edge having a smoothly curved intermediate recess and defining a sharp edged section thereof of slightly inclined relation with the longitudinal center-line, for development of significant cutting force application against tree roots when the shovel blade is pivoted by forcible pivotal movement of the shovel handle. If desired, the sharpened root cutting edge of the centrally located root cutting blade may be of substantially straight, concavely curved or convexly curved configuration and located in inclined relation with respect to the center-line of the shovel blade. If desired, the sharpened root cutting edge of the central root cutting blade may be oriented in substantially normal relation with the longitudinal center-line of the shovel blade. The upper edge of the central root cutting blade is preferably not sharpened, but it may define a sharp cutting edge if desired. The rear or trailing end of the central root cutting blade may be located essentially at the rear or trailing end of the shovel blade, or it may be located forwardly of the rear or trailing end of the shovel blade.
A pair of side blades project from respective substantially parallel side edges of the shovel blade and extend from locations at or near the rear or trailing end of the shovel blade. These side blades extend downwardly along portions of the side edges, typically to locations where the side edges begin to curve in forwardly converging relation. The side blades can be oriented in substantially normal relation with the respective side edges of the shovel blade, but preferably they are oriented in outwardly angulated or feed relation with the side edges of the shovel blade and in outwardly or forwardly diverging relation with one another. The side blades are each formed with downwardly facing sharpened cutting edges which efficiently cut through any surface roots that are present in the soil, after the shovel blade has penetrated into the soil to a certain extent, and thus permit the shovel blade to retain virtually of its soil load as the shovel handle is rotated in a prying action to break the soil away adjacent the lower cutting edge of the shovel blade. This feature also virtually eliminates any tendency of the shovel blade to be rotated by uneven side forces typically caused by the uneven resistance of surface roots adjacent the side edges of the shovel. The side blade cooperate with the central root cutting blade to divide the soil load into two basic sections which readily fall away from the concave face of the shovel blade when the shovel blade is rotated to dump its load.
At its lower end the shovel blade, rather than being pointed as is conventional, defines a small centrally oriented cutting edge section preferably of substantially straight configuration and being oriented in substantially perpendicular relation with the longitudinal center-line of the shovel blade. If desired, the lower centrally oriented cutting edge section may be of slightly convexly or concavely curved configuration, but it does not define a centrally oriented point. The lower centrally oriented cutting edge section for a typical round point shovel may be in the order of from about one and one-half inches in length to about three inches in length.